To perform a sleazy and reprehensible act after your more ethical colleagues refuse to do it.
Source: Robert Bork fired the Watergate special prosecutor for Richard Nixon after his superiors in the justice department resigned rather do it themselves.

What do you get when you bork? Well, Judas got thirty pieces of silver. Sometimes, though, you get nominated to be a supreme court justice.

Verb. refers to the act of having anal sex, usually involuntarily, or perhaps being taken advantage of. a.k.a "Butt porked"

You just got donkey borked.

"My cowboy friend is gay coz he likes to be borked, he lives on Borkback Mountain"

A man was hunting deer to make sausage. He spotted a buck and cocked his gun. Misfire! the buck charged him... The hunter woke up and discovered he was bent over a log.
The buck said "Here is that deer sausage u wanted", then he borked him.